This application relates to a chain and flight conveyor for use in conveying materials in the mining industry, and, in particular, to an improved design of a chain and flight conveyor having an improved drive sprocket assembly. Still more particularly, this application relates to conveyor chains for continuous miners and chain haulage units.
Conveyor chains for use on continuous miners and chain haulage units must have the ability to flex sideways to allow them to make turns. For this purpose, they include swivel links. Unlike a link from a standard roller or stud-bushed chain, a swivel link cannot be sprocket-driven on its interior, because the space within it is mostly filled with the swivel pin and the lugs that surround the swivel pin. A swivel link can only be sprocket driven on its outer ends.
O'Neill U.S. Pat. No. 6,662,932 ('932 patent) illustrates an improved chain and flight conveyor with swivel links. As illustrated in prior art FIGS. 1 through 4, the '932 chain and flight conveyor 10 includes a pan or conveying deck 14 of, for example, a continuous miner or a shuttle car, and a conveyor chain and flight assembly 18 that travels over the pan 14. The conveyor 10 also includes a sprocket drive 22.
More particularly, as shown in FIGS. 3 and 4, the conveyor chain and flight assembly 18 includes a first link assembly 26 and a second link assembly 30, each of which includes two spaced apart drive pins 34, each of which has a first end 38 and a second end 42. Still more particularly, the chain and flight assembly 18 is formed from a plurality of alternating first link assemblies 26 and second link assemblies 30. Each link assembly also includes two spaced apart side plates 46, each of which has two spaced apart openings 50, each opening 50 receiving a different one of the drive pins 34. Drive pin retaining means in the form of press-fitting retains the drive pins 34 in the side plates 46. The conveyor chain and flight assembly 18 also includes a swivel assembly 62 connecting the two link assemblies 26 and 30, the swivel assembly 62 including a swivel pin 66, a male connecting lug 70, and a female connecting lug 74.
More particularly, the male connecting lug 70 has a base 75 with a horizontal bore 78 that receives one of the drive pins of the first link assembly 26, and a tongue 82 connected to the base 75. The female connecting lug 74 has a base 86 with a horizontal bore 88 that receives one of the drive pins of the second link assembly 30, and a spaced apart upper lip 90 and lower lip 94 connected to the base 86. The male connecting lug tongue 82 extends between the spaced apart lips 90 and 94, each of the lips and the tongue having openings therein that form a bore 98 through the male and female lugs that receives the swivel pin 66. Swivel pin retaining means in the form of a weld retains the swivel pin 66 in the lugs 70 and 74.
The conveyor chain and flight assembly 18 also includes a first flight 110 (see FIG. 2) connected to one of the first and the second link assemblies, the flight 110 having a flight head 114 having two spaced apart indentations 118 and 120, each of which receives a different one of the first ends of the drive pins 34. The conveyor chain and flight assembly 18 also includes first flight securing means retaining the drive pin first ends in the first flight head so that the first flight head is spaced from its respective side plate. More particularly, the drive pin first ends are press-fitted or welded to the first flight head 114. Still more particularly, a pair of such first and second flights is connected to each of the second link assemblies. In other embodiments (not shown), the pair of such first and second flights can be connected to the first link assemblies.
The conveyor chain and flight assembly 18 also includes a second flight 124 connected to the one of the first and the second link assemblies, the flight 124 having a flight head 128 having two spaced apart indentations 132 and 136, each of which receives a different one of the second ends of the drive pins 34. The conveyor chain and flight assembly 18 also includes second flight securing means retaining the drive pin second ends in the second flight head 128 so that the second flight head is spaced from its respective side plate. More particularly, the drive pin second ends are press-fitted or welded to the second flight head 128.
As illustrated in FIGS. 1 and 2, the conveyor chain and flight assembly sprocket drive 22 includes two spaced apart drive sprockets 140 and 144, with each of the drive sprockets engaging the drive pins 34 between the side plates and the side plate's respective flight.
In summary then, the invention is a chain 10 driven by two sprockets 140 and 144 spaced a short distance apart along their common axial centerline (see FIG. 2). The chain 10 includes elongated pins 34 that extend beyond the outer surfaces of the chain link plates 46, on both sides, by a distance about equal to the width of the spaced apart sprockets 140 and 144. The chain is aligned midway between the sprockets 140 and 144, and the sprocket teeth drive on the extended portion of the chain pins 34. Where a flight is attached to the chain links, the pins are extended still further, to fit into the indentations or holes in the flights. This provides an exposed length of each pin in alignment with the sprocket on each side for driving purposes.
The sprockets 140 and 144 are located away from the center of the chain and therefore away from any interference with the swivel link. The sprockets can thus drive the chain on every pitch.
As an alternative to the swivel assembly 62 connecting the two link assemblies 26 and 30, a solid link (not shown in FIGS. 1 through 4) can also provide some limited pivotal movement by providing a loose connection to the link assemblies 26 and 30 by having pin receiving openings that are larger than the pins received in the openings. This permits some limited pivotal movement between the links, serving as a partial swivel joint.